Numerous and varied types of insulation blowers have been produced, for use in blowing insulation, such as fiberglass, rockwool and the like, into a space to be insulated, through a hose connected with the blower. Some blowers operate essentially on the pump principle, i.e. the insulation itself passes through the blower, which is usually of the centripetal type. Other blowers utilize an airlock, in which insulation is fed into successive spaces between planar blades mounted in radial positions on a shaft, normally rotated about a horizontal axis. The blades are provided with some type of seal for engaging a generally cylindrical housing closed at each end but having a top opening for introducing the insulation. The insulation is fed from a hopper into the top opening of the airlock and, as the shaft and blades rotate, is carried around within the successive spaces between blades, so as to be contained within an otherwise generally closed space at the bottom or toward one side of the bottom of the cylindrical housing. An inlet for air is provided at one end of such a position and an opposite outlet for insulation forced by air pressure through the space between the blades and into a hose. A blower provides air pressure to the inlet for the space from which the insulation is expelled into the hose. Such a hose may lead to the space, as within a wall, above a ceiling or beneath a floor, into which the insulation is to be blown.
Generally, insulation is placed in a hopper above the airlock, while insulation in the hopper is agitated by agitating rods mounted on a horizontal shaft. Such rods may also be formed as paddles for moving the insulation toward an outlet of the hopper, which normally coincides with the inlet of the airlock. Such an insulation agitator shaft requires a horizontally disposed, semi-cylindrical bottom for the hopper, which in turn has dictated a square or rectangular lower housing for the unit with considerable waste space around the outside of the semi-cylindrical bottom of the hopper and thereby a reduction in the volume of insulation which may be placed in the hopper. As a consequence, additional material is required for constructing a hopper having the desired volume, as well as complicating the problem of adequately attaching the base to the hopper. Since the agitator shaft, within the hopper, is rotated about a horizontal axis and the airlock shaft is also rotated about a horizontal axis, the drive arrangement, from a motor, for such a construction may often be complicated and expensive. A motor drive for the airlock may be placed beneath the hopper, but the drive to the horizontal hopper stirring shaft may require placement outside the hopper and thus require protection in that position. Sometimes, a separate space within the unit is provided in order to contain the drive to the hopper agitator shaft. In some instances, separate motors are utilized to drive the airlock shaft and the hopper agitator shaft, as when the two shafts are driven at different speeds. Whether one or two motors, each such motor is ordinarily provided with reduction gearing, since the speed of rotation of electric motors which are manufactured in sufficient quantities to be economical, is normally considerably greater than the speed at which the airlock shaft and/or the stirrer shaft are desired to be driven.
Certain problems also arise in the construction of the blades of the airlock rotor. Sometimes these blades are attached individually to the airlock shaft, but require disassembly of the airlock and removal of the rotor for repair or replacement of one or more blades. In U.S. Pat. No. 3,708,890, a rectangular shaft for a rotary airlock is provided with two pairs of V-shaped blade holders attached by bolts to the opposite sides of a rectangular shaft, so that four blades may be attached, at 90.degree. apart, to the respective extending arms of the holders. However, the assembly of two blades to a holder does not permit the two blades to removed, as a unit, from the airlock through the inlet opening. Thus, either the airlock must be disassembled for repair, or an individual blade disassembled inside the airlock, which is a time consuming task due to the position of the bolts which attach the blades to the blade holders, since access to the opposite sides of a blade holder is necessary.
Among the objects of this invention are to provide a novel blower for blowing insulation; to provide such a blower which is readily portable; to provide such a blower having a hopper in which a shaft for rotating agitator blades is upright and extends generally centrally for only a short distance into the hopper; to provide such an insulation blower in which both a shaft for the agitator blades in the hopper and the airlock shaft may be driven from the same motor, as through a simple drive connection; to provide such an insulation blower in which the vertical position of the hopper agitator shaft and the horizontal position of the airlock shaft permits one shaft to be driven from the other, through a simple bevel or miter gear connection; to provide such an insulation blower in which either the airlock shaft or the hopper agitator shaft may be driven directly by reduction gearing and the other from the direct driven shaft, thereby requiring only a single motor; to provide such an insulation blower in which the speed ratio between the airlock shaft and the hopper agitator shaft may be varied; to provide such an insulation blower having an upright, cylindrical hopper, thereby minimizing the amount of material required, due to the inherent volumetric capacity of such a hopper; to provide such an insulation blower in which the hopper may be generally cylindrical and thereby be provided with an essentially flat bottom around which the blades of the agitator rotate; to provide such an insulation blower in which the agitator blades may move the insulation in the hopper into an opening, from a direction opposite the direction of rotation of the airlock rotor; to provide such an insulation blower in which the blades of the rotor are attached to the rotor shaft in a novel manner; to provide such an insulation blower in which the blades of the airlock rotor are attached to the shaft in a manner which permits any blade to be removed individually by removing only a few bolts which are readily accessible for such removal; to provide such an insulation blower which may be optionally controlled from a remote location and the amount of insulation delivered may also be controlled; to provide such an insulation blower which may be manufactured in a simple and inexpensive manner; and to provide such an insulation blower which will operate effectively and efficiently.